var arg=process.argv[2];
if((typeof arg)=='undefined'){
    console.log("Please input arg!");
}
if(arg=="--help"){
    console.log("program --help");
}
if(arg=="-h"){
    console.log("program -h");
}
var result =eval(arg);
if(!isNaN(parseInt(result))){
    console.log(arg+"="+result);
}